Spragging device for motor vehicles



March 8, 1932. G, W|| 50N ET AL 1,848,761

SPRAGGING DEVICE FOR MOTOR VEHICLES Filed July 17, 1930 2 Sheets-Sheet l Fig. 1. /3 .ZI 1 u Il /4 l 1 Q: l

w n J Fig. 2

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March 8, 1932- G. WILSON ET AL SPRAGGING DEVICE FOR MOTOR VEHICLES Filed July 17. 1950 2 Sheets-Sheet 2 A TTOR/V l ratchet teeth.

` from which is suspended the vsprag casing.y

Patented Mar.r s. 1932 UNITED GEORGE WILSON, on N EWoAsTnmoN-TYNE, anni HAROLD JOHN HENRY-MOORE,- OF

SPRAGGING'DRVIOE FOR MOTOR vnnrciniis-v i i Application Yined 11115117.1930, sriaifiie. 46s,'z`24 ,fand,in Greatisrifgyiaauiy 2 0, 1929.;

L vThis invention relates tofspragging devices for motor vehicles, ofthe kindfcomprisiiig pavvls mounted'to rotate with the transmis sion shaftand adapted toengage a'station- .ary ratchet, the pawlsl being loadedon one side so that when apredetermined speed is attained centrifugalforce will cause thepawls to be Withdrawn from engagement with the ratchet wheel, `while means controllable at Will are provided for rendering the pawls inoperative vehicle.l

The invention consists in forming the loaded portionof each pawl separate from the engaging portion orpawl proper, Vso that when the Vpawls are in engagement with the ratchetteeth, the loaded portions `do notniove astheA paWls are oscillated-as aQr'esultoffthe turning of thepawls about the yratchet Wheel,

but Vwhen the loaded vportions move outwards .they carry the pawls properwithtliem Vto withdraw tliem'rfrom engagementk with the The invention will V'now be reference (to the accompanying drawings `which show the device appliedto fa"heavy vehicle. t y

l In the said drawings: t

Fig. 1 is a cross-sectional On the line I-I of F ig. 2.

Fig. 2 is a sectional elevation taken on the line II-H of Fig. `1 but with the lower poreivanoa'takn Vtion of the pawl gear shown iii-elevation.

Fig. 3 is a plan of Fig; lewith tlie'cam' plate casingcover removed. 1

VVReierring more particularly to' the drawings, Y1 is a cross memberV on the chassislframe T his casing `comprises a short cylindrical member 2 secured by means of two clamps 3, 4 to the cross member 1. The member 2 forms a housing for a roller bearing 5 which supports the Cardan shaft 6. Bolted to therear e gaat, .wie .the .groove vofwhich; engagea ferkd brdl'eafiil p'vietally mouhtedfin thev casing'- 8 v at 261 Y Rigid with the said cfol-4 :lar12lj are four, pins 27 having? hiinfered ends' whichextend underneath the weights y Y lf'sothat onfmovinglthering2l longitudir of the member 2 is a ratchettoothed ring 7 and a further casing member 8.

Keyed to the shaft is a pair of langeddiscs independently of thev speed ofthe drawings'. 'piece 4lis -arranged between Z th am and the: Weight' :being plvotalfly mounted about thepin 1l.. The paWl1'2 .has

a proyection 12al againstvvhich theweightI 1 3 abuts `when it `moves outwardsy underA cen#V trifugal force; but when tliefcentrifugalfforce istoo small to influence the weight,movement arranged betvv'eeii, the discs 9,10, serve to they teethfof "theratohet ring 7 while: coil springs 16 wrapped aroundprojection 1 1@ on thepins 1l andh'aviiig one of their ends `pressing-against projections 13a O Dthe `weight s 1 3 serveto maintain Vthe said weightsfiii their `innerpt'isition when there is vno centrifuga] `force of any conseq uence- Thefprojections Y13mpass thi"o1u li slots 1Ot 7(s howi`i' in chainNv 111 Fia-V Mathey are abev'the plana'offihe,

A distance the rollerbearing andthedi'scj, andan-v other distance piece 18 between the bearing 5 andanfadjusting nut 19, a' set v,screw 20 be- 'ingQprovided thereon for locking purposes. Onthe 'rear side ofthe diselOis a distanceV sleeve'21 againstwhichabuts' a flanged cy#- lindrical-member 22, forming part of a. universalV coupling, the saidv Vmember 22 'Y being held firmly on the/tapered 'e'i'idlof the shaft G byrmeans ofanut 23. AWhen the 'nut 23 is tightened up as `far as' it` will go the mit vso 1 9 isf then tightened up and so'thevarious r:members betweenthe ttwgmits" tlgn (123, .held firmly; together, the` nut lgbeng lqked by means of the 'set screw 20. v The" distance sleeve d1 isof thesame diamy 190 eter as the cylindrical portionmof the membeij 22 so' as to provide a continuous VVsurfaceaoni which is slidablyfmouiited a grooved colla-r y cause the weights 13 to be pushed outwards,

land therefore the pawls 12 to be withdrawn from the ratchet ring 7 Projecting upwards from the upper arm a of the bridle 25 is a pin 28 which engages with a cam slot 29 in a cani plate 30 Vslidably mounted in the top of the casing 8. The said plate 80 has a slot at 30a with which 'engages a pin 31 onthe end ofan arm w32 ;ment with the teeth of the ratchet ring 7. lStops on the disc 10 limit the inward travels of the pawls12.` I

' The op'eration of he deviceis as follows When the vehicle 'is running below apredetermined speed, for example a Cardan shaft speed of about 400 revolutions per minute, the lpawls '1Q willY be in Vengagement withthe teeth ofthe ratchet ring 7 forall forward speeds.Y However when the said Vpredetermined speed is exceeded, centrifugalforce will cause the weights 1,3 to move loutwards against'the'action of their springs 16, 'and owing to their abuttinga'gainst the Aprojections 12am'my the pawls 12 the latter are withdrawn from engagement withthe ratch- `et ring`7 as `shown in dotted lines 'forone of 'the pawls in Fig. 1. Ingthis connection, it is'to be'noted that theweights ofthe loaded lporti'onsof the pawls mustfbeisuch that the centrifugal force generated at -the critical sp'eed'will be sufficient to 'overcomethe pressure of the springs 14' and 16.

YVhen the'vehicle isrunning at low speed so that ythe pawls are `in operation, the

vweights 13 will remain stationary as'the Vpawls are moved inwards by the teeth of the ring 7 as sh'ownfwith regard to two oppositepawls in Fig. 1. [Inertiastresses are thus reducedand the wear between the pawls and ratchet teeth is not so heavy as would `be the case if the weights and 'pawls "were in onev The drawings show the position of the defvice., when the gear selector is in neutral, in

which position the pins V27' are -withdrawn from engagement', with the weights 13 so that the'pawls 12 are in engagement with fthe ratchet ring 7 As will be seen from '3 which shows the positions of the plate for the various gear positions controlled .i vthe gear. selector to which it is connected,

` forff1rst, and second gear positions, the pin 28 remains inf the position shown, while for second neutral and reverse', the said pin v'35 the vri'ghthand end of the upper p'orti'nof is moved intothe position of disengagement.

and second Vgear selector of the cam groove, while in the second neutral position the said pin occupies the upper por tion of the cam groove adjacent the inclined portion. Hence in the event of the gear lever being'moved to the second neutral position after lbeing in reverse, while the vehicle is still moving backwards, the device Vremains outv of operation and no damage is caused. Only when a forward gear is engaged is the device Aagain made operative.

We claim r1. Aspragging device for mother vehicles comprising a transmission shaft, a casing around said' shaft, aratchet wheel rigid with said casing and concentric with said shaft, carryingmeinber on said shaft, pawls 'pivotally'f mounted 'on said pawl carrying member and adapted to engage with said ratchet wheel, abutments on said 'pawls remote from their engaginglfaces, and weights pivoted on saidlpawl carrying member, said "weights being ladapted after a predetermined amount of outward movement to abut against the abutments on vthe pawls `so as to force rtheir engaging faces inwards.

y2. Al spragging device according to claim l, and springs adapted to abut against said weightsto'press them inwards when the shaft is 'rotating below -'a predeterminedspeed.

A, 3. A spragging vdevice according to claim 1,"a grooved collar, chamfered pins on said collar, ythe chainfered portion of each of said :pins lyn'gon "the inside of each pivoted weight and I means for "moving "said Ygrtoov'ed collar axially, aprojection on'th'e meansfor moving the grooved collar axially, a slidable cam plate adapted to be connected with the vehicle gear c'ontrollingmeans, a cam "slot in said cam plate, ksaid cam slot being in engagement'with the said projection, so that for certain "gear positions vthe device 'may be rendered inoperative.

VIn witness -whereof 4we have signed this specification. n e

GEORGE WILSON.

HAROLD J. IH. MOORE.

In the revers'epositionthe pin E28 occupies 

